CHARACTERIZATION BY SIMS OF BRONSTED ACID CHEMISORPTION ON MGO(100) AND CS/MGO(100)

The room temperature chemisorption of a variety of molecules possessing Bronsted acid character has been investigated on MgO(100) and Cs/MgO(100) substrates by secondary ion mass spectrometry (SIMS). The adsorbates studied include: acetylene (ethyne), hydrogen sulphide, 2-propanol, acetone (2-propanone), formic acid and methanol. The emphasis of the study is placed on the qualitative identification of the adsorbed species which is in most cases the conjugate base of the Bronsted acid. An exception is 2-propanol whose interaction with MgO and Cs/MgO apparently involved dehydration. There is also evidence for decomposition of formic acid in its initial interaction with Cs/MgO.